In 1895, a German scientist named Wilhelm Conrad Roentgen discovered the existence of X-rays. His work led to the 1901 Nobel Prize in Physics, and X-rays would come to play a prominent role in the research of Marie Curie, Henri Bequerel, Thomas Edison, and other towering figures in science and medicine. This edition examines how Roentgen used the scientific method to achieve his aims and the applications of his discovery. The book also explains how Roentgen’s discovery continues to lay the groundwork for new discoveries in astronomy, biology, and more.